Applicator for surgical clips

ABSTRACT

A hand-operable surgical clip applicator ( 10 ) including a barrel ( 12 ) having a first end ( 14 ) and a second end ( 16 ), the second end formed to accommodate a surgical clip, a crimping lever ( 20 ) pivotally connected at the second end of the barrel, and a trigger ( 28 ) co-located with the barrel, the trigger being operable to pivot the crimping lever, the pivoting movement of the crimping lever causing the surgical clip to be urged from an open position to a closed position, wherein the trigger has an operating portion on either side of the barrel.

TECHNICAL FIELD

This application relates to applicators for surgical clips, and moreparticularly to applicators for the insertion and closure of surgicalclips.

BACKGROUND OF THE INVENTION

Such applicators are intended for single handed operation by anoperating surgeon. Examples of such applicators are described ininternational patent application publication numbers WO 2005/039422 andWO-A-01/12079.

Such clips may be used for sterilisation or other medical, orthopaedicor surgical purposes. An example is the “Filshie” clip which isdisclosed in GB patent number 2177748.

Certain known applicators for such clips, as disclosed for example in WO2005/039422, use a pushrod and associated linkage mechanism to causerotation of an articulated jaw to produce compression forces on a clipand to thereby compress the clip causing it to close, preferably with alatching action. The compression forces on the relatively slenderpushrod cause radial reaction forces and consequent friction at theinterface between the pushrod and the outer tube. This can result in theapplicator mechanism sticking in the closed position thus causingproblems for the operating surgeon in disengaging the applicator fromthe closed clip.

Another problem with known applicators is the need to adjust the travelof the mechanism in order to achieve correct closure of the clip to anaccurate position; such adjustment can be costly to achieve. It isimportant that the surgical clip is closed to an accurate position. Ifthe clip is closed too tightly, the tubular anatomy may be severed,requiring the surgeon to apply further clips to severed ends of thetubular anatomy. Conversely, if applied clips are not closedsufficiently tightly, the tubular anatomy may not be properly occluded.

A further problem with known applicators is the requirement that theapplicator must be made from expensive components in order to ensurethat the surgical clips can be closed accurately, and to be able toperform many clip closure operations. In particular, in such animportant piece of medical equipment, and especially one in whichmechanical forces are transmitted (e.g. the force of the surgeon pullingthe trigger, which is converted to a closing force on the clip), it isimportant that tolerances are carefully monitored and, if need be,adjusted in the manufacturing environment. This can be expensive, andincreases the manufacturing cost of the applicator.

Appropriate design of applicator and its constituent components canmitigate some of the issues associated with this.

Other designs of applicators can require the surgeon to applysignificant force to the trigger mechanism of the applicator in order tocorrectly close and latch the surgical clip, which can make theapplicator difficult to manipulate and operate.

It is often necessary for the applicator to be inserted into a cannuladuring “keyhole” surgery. Existing clip applicators have a “pistol”handgrip which can make them difficult to manipulate into the correctposition whilst at the same time operating the applicator (in particularproviding adequate manual closure force) to close the clip.

It is an object of the invention to provide an applicator for surgicalclips which requires less force to operate and to correctly close andsecure a surgical clip than known applicators.

Another object of the invention is to provide an applicator which canprecisely close and secure surgical clips to an accurate position.

A further object of the invention is to provide an applicator which maybe more precisely manipulated than known applicators, whilst also beingoperable to close and secure accurately a surgical clip.

A still further object of the invention is to provide an applicator forsurgical clips which is of a simpler and more robust design to suchknown applicators.

Yet another object of the invention is to provide an applicator forsurgical clips which is easier and cheaper to manufacture than existingapplicators

Such an applicator may be partially or completely disposable.

SUMMARY OF THE INVENTION

According to a first aspect of the invention there is provided ahand-operable surgical clip applicator, the applicator comprising abarrel having a first end and a second end, the second end formed as afirst crimping surface and being able to accommodate a surgical clip; acrimping lever, the crimping lever pivotally connected to the barrel,the crimping lever having a second crimping surface and a opening peg,the second crimping surface being in opposition to the first crimpingsurface, the first crimping surface and the second crimping surfacesbeing biased away from one another; and a pushrod, slidably locatedwithin the barrel, which may abut, and in use does abut, the crimpinglever and constrains the opening peg; wherein movement of the pushrodtowards the second end of the barrel causes the pushrod to push thecrimping lever, further causing the second crimping surface to closeonto the first crimping surface, thereby in use urging a surgical clipfrom an open position towards a closed position.

In known applicators it is common for the second end of the pushrod toslide over the crimping lever in order to rotate the crimping leverabout a hinge point and urge the surgical clip from an open position toa closed position. This can result in the crimping lever becoming jammedin the closed position due to the frictional forces between the secondend of the pushrod and the crimping lever.

In the present invention, linear movement of the pushrod towards thesecond end of the barrel results in the second end of the pushrodpushing against the crimping lever. This causes a rotational movement ofthe crimping lever. During opening of the crimping surfaces, the secondend of the pushrod acts to pull on the opening peg of the crimping leverto thereby cause the crimping lever to move such that the crimpingsurfaces are in an open position.

Preferably, movement of the pushrod away from the second end of thebarrel causes the pushrod to pull the opening peg, further causing thesecond crimping surface to open away from the first crimping surface.

Preferably the pushrod includes a hollow portion, with a return springbeing accommodated within the hollow portion.

Locating the return spring within the pushrod ensures that the surgicalclip will be released from the applicator in the event that any part ofthe handle, trigger or actuating means should fail in use, therebyimproving reliability of the applicator.

Preferably the barrel is formed from a single piece of material.

This can be achieved by utilising a forming process which facilitatesthe manufacture of the first crimping surface and the pivot on which thecrimping lever is mounted from the same piece of tubing material. Thisavoids welding of barrel components, which has previously been necessarywhere the barrel and parts of the barrel have been made by machining.

Forming the barrel from a single piece of material reduces the number ofcomponent parts in the applicator, making it easier to assemble andlowering the manufacturing cost.

According to a further aspect of the invention there is provided ahand-operable surgical clip applicator, the applicator comprising abarrel, the barrel having a first end and a second end, the second endformed to accommodate a surgical clip; a crimping lever; a trigger; anda handle; wherein the handle includes a first lever having a first endand a second end, the first end of the first lever being pivotallyconnected at the handle, the second end of the first lever beingslidably connected to the trigger; and a second lever having a firstend, a second end and a centre region, the centre region of the secondlever being pivotally connected to the handle, the first end of thesecond lever being configured to slide along the length of the firstlever, the second end of the second lever being adapted to operate thecrimping lever; the first lever and the second lever being configured toprovide a mechanical advantage between the trigger and the crimpinglever, movement of the trigger in use causing movement of the crimpinglever, resulting in a surgical clip being urged from an open position toa closed position.

The use of a mechanism to provide a mechanical advantage such as thatdescribed above between the trigger and the crimping lever enables themanual actuation force required to be provided by the user to bereduced, thereby making the applicator easer to operate.

The concomitant increase in trigger travel allows the surgeon to moreprecisely determine the degree of trigger movement required to correctlyclose and secure the surgical clip.

A compound lever arrangement as described above is a simple andeffective means of providing a mechanical advantage.

Preferably the barrel includes a slot at its first end, the slotaccommodating the second end of the second lever.

The slot in the first end of the barrel allows the pushrod to be locatedcompletely within the barrel.

Preferably the first end of the pushrod includes an end cap, the secondend of the second lever pressing against the end cap.

The end cap located at the first end of the pushrod provides anincreased surface area against which the second end of the second leverpresses. This eliminates the possibility that the second end of thesecond lever will become disengaged from the first end of the pushrodduring operation of the applicator.

Preferably the pushrod further comprises a transfer rod and a pusher,the pusher having a stop face, the transfer rod and pusher beingslidably located within the barrel, the transfer rod and pusher beingreleasably connected together by a bayonet joint and the pusher abuttingthe crimping lever and constraining the opening peg of the crimpinglever.

By connecting the pushrod and the pusher with a bayonet joint, thepusher experiences no bending forces which may cause it to bind in thebarrel.

Preferably, the pusher is formed with sliding surfaces at each of thefirst and second ends, the sliding surfaces configured to slide withinthe internal surface of the barrel, the portion of the pusher betweenthe first and second ends having a smaller diameter than each of thefirst and second ends.

Such a pusher has a waisted profile which facilitates insertion of thepusher into the barrel during assembly of the applicator. The waistedfeature also reduces the friction between the pusher and the barrelduring operation of the applicator.

Preferably the trigger includes a visual indicator in at least one sidethereof, the visual indicator providing means indicative of anintermediate trigger position.

If the clip is incompletely closed, the clip may partially latch whichwill prevent the clip from subsequently being correctly latched. Thevisual indicator in the trigger allows the surgeon to partially closethe clip so that it can be inserted through a cannula, without the riskof the clip becoming partially latched, prior to the clip being appliedto a tubular anatomy.

Preferably the barrel is located in the handle by a barrel pin, thebarrel pin being secured to the handle.

The barrel pin secures the barrel directly to the handle. This featureensures that the forces generated during the clip closure process aretransmitted to the handle.

Preferably the handle includes a locating plate, the locating platebeing secured to the barrel by a retaining pin, the locating plate beingfurther secured to the handle by a locating plate fastener.

The function of the locating plate is to position the barrel securelyrelative to the handle. This enables the surgeon to manipulate theapplicator precisely.

An additional function of the locating plate is to provide a secondarypositive stop to the trigger. This secondary stop provides the surgeonwith clear, tactile feedback that the mechanism has reached the end ofits travel. Once the mechanism has reached the end of its travel, thesecondary stop transmits the loads applied to the trigger directly tothe handle. This prevents the mechanism from being damaged due to theapplication of excessive force to the trigger.

Preferably the pushrod includes a slot, the slot accommodating theretaining pin .

The retaining pin serves to secure the barrel to the locating plate.

Preferably the stroke of the pushrod is limited by the stop face of thepusher abutting the crimping lever.

By governing the stroke of the pushrod, the stop face of the pusherabutting the crimping lever provides a first end stop to the travel ofthe trigger and the consequent rotation of the crimping lever. Thisprevents the crimping lever from closing the surgical clip past thenominal closed position. Such “over-closing” can result in the clipbeing closed too tightly.

According to a further aspect of the invention there is provided ahand-operable surgical clip applicator, the applicator comprising abarrel, the barrel having a first end and a second end, the second endformed to accommodate a surgical clip; a crimping lever; and a trigger,the trigger co-located with the barrel, the trigger being adapted tooperate the crimping lever, causing the surgical clip to be urged froman open position to a closed position, wherein the trigger is formedwith a pressing surface disposed on each of two opposing sides of thebarrel.

In use, the clip applicator must be manipulated into the correctposition and simultaneously operated to apply the surgical clip to atubular anatomy, such as a Fallopian tube. By arranging the trigger oneither side of the barrel, the clip applicator can be more preciselypositioned, whilst manually applying force to close the clip. This isbecause the barrel is positioned between the first and second fingers ofthe surgeon's hand, making it align naturally to the wrist of thesurgeon, thus assisting the surgeon in precisely positioning the barrel.Such a trigger configuration may also be ergonomically more suitable,allowing the muscles of the surgeon's hand to more readily generate aclosing force than a conventional trigger configuration.

A further advantage of this embodiment may be that as the trigger ismoved into and out of the handle there is no appreciable gap between thetrigger and the body of the handle. In surgical operation surgicalgloves will be worn which may be snagged and torn if there were to beany substantial gap between the trigger and the handle, which couldcause hygiene issues.

Preferably, at least one of the trigger, handle, first lever, secondlever or locating plate is formed from a material which becomes moltenwhen the applicator is exposed to the operating environment within amedical autoclave.

Conveniently, the applicator is a disposable device which is intendedfor use on a single patient. A desirable safety feature of theapplicator is that at least one of the main operating components of theapplicator is formed from a material which melts when exposed to theconditions operating environment within a medical autoclave. Thus, theapplicator can be rendered unusable if the unit was to be sterilised inan autoclave.

DESCRIPTION OF THE DRAWINGS

There now follows a description of preferred embodiments of theinvention, by way of non-limiting example, with reference being made tothe accompanying drawings, in which:

FIG. 1 shows a perspective view of the applicator of the invention;

FIG. 2 shows a partial sectional perspective view of the second end ofthe barrel of the applicator of FIG. 1;

FIG. 3 shows a sectional view of the handle of the applicator of FIG. 1;

FIG. 4 shows a partial sectional view of the bayonet joint of theapplicator of FIG. 1;

FIG. 5 shows a detailed partial sectional view of the first end of thebarrel of the applicator of FIG. 1;

FIG. 6 shows the operation of the first end stop of the applicator ofFIG. 1.

DETAILED DESCRIPTION

With reference to the drawings, FIG. 1 shows a hand-operable surgicalclip applicator according to the invention.

The applicator 10 comprises a barrel 12, a trigger 28 and a handle 62.

The barrel 12 has a first end 14 and a second end 16. The second end ofthe barrel 16 is formed as a first crimping surface 18 and accommodatesa surgical clip.

The barrel 12 is formed from a single piece of stainless steel tubing.

As shown in FIG. 2, a crimping lever 20 is pivotally mounted at thesecond end of the barrel 16. The crimping lever 20 has a second crimpingsurface 22 and an opening peg 24 formed integrally.

The second crimping surface 22 of the crimping lever 20 and the firstcrimping surface 18 at the second end of the barrel 16 act as aco-operative pair of jaws to crimp the surgical clip and to urge theclip from an open position to a closed position.

As shown in the figures, a pushrod assembly 42 is slidably locatedwithin the barrel 12 and comprises a transfer rod 44 and a pusher 50.

The transfer rod 44 has a first end 46 and a second end 48. The pusher50 has a first end 52 and a second end 54.

The second end 54 of the pusher 50 is formed with a slot 53 whichconstrains the opening peg 24 of the crimping lever 20 and a stop face55. The first end 52 of the pusher 50 is operatively coupled to thesecond end 48 of the transfer rod 44 by a bayonet coupling 56, as shownin FIG. 4.

The pusher 50 is waisted and is formed with sliding surfaces at each ofthe first and second ends 52,54 which slide along the internal surfaceof the barrel 12. This waisted feature facilitates assembly of thepusher 50 into the barrel; the waisted feature also reduces the frictionbetween the pusher 50 and the barrel 12, compared to if the whole of thepusher 50 had a consistent radius along its length.

The trigger 28 is co-located with the barrel 12 and includes a pressingsurface 30 on each of two opposing sides of the barrel 12. Each of thepressing surfaces 30 is sized to be operable by the first and secondfingers of the surgeon's hand respectively.

The trigger is preferably moulded from a thermoplastic material.

The trigger 28 includes a visual indicator 32 in each side of thetrigger 28. The visual indicator 32 takes the form of a slot in eachside of the trigger 28 with a reference mark 34 moulded into the sidesurface of the trigger 28.

The visual indicator 32 provides a visual indication of an intermediateor “half closed” trigger position. When the trigger 28 is depressed suchthat the reference mark 34 is aligned with the handle 62, the trigger 28is “half closed”. This can be important as it allows the surgeon tooperate the applicator 10 to hold and partially close the surgical clipwithout latching the clip, thus enabling the applicator and the clip tobe inserted through the cannula prior to being positioned, closed andsecured.

The trigger 28 further includes an actuating slot 36 on each side of thetrigger which is part of a lever mechanism.

The handle 62 is formed in two parts. The handle 62 is preferablymoulded from a thermoplastic material.

The handle 62 includes a first lever 72 and a second lever 88. The firstlever 72 has a first end 74 and a second end 76. The second lever 88 hasa first end 90, a second end 92 and a centre region 94.

The first end 74 of the first lever 72 is pivotally connected to thehandle 62 by a first pivot 80. The second end 76 of the first lever 72is slidably connected to the trigger 28. Two actuating pegs 82 formed onopposing sides of the second end 76 of the first lever 72 engage withthe actuating slot 36 of the trigger 28.

The first lever 72 is formed with a U-shaped cross-section. The firstlever 72 is preferably moulded from a thermoplastic material.

The centre region 94 of the second lever 88 is pivotally connected tothe handle 62 by a second pivot pin 96. The first end 90 of the secondlever 88 is arranged to slide along the length of the first lever 72with the first end 90 of the second lever 88 located within the U-shapedprofile of the first lever 72. The second end 92 of the second lever 88presses against the first end of the transfer rod 46.

The second lever 88 is preferably formed from stainless steel.

The first lever 72 and the second lever 88 are configured to provide amechanical advantage between the trigger 28 and the transfer rod 46.

FIG. 5 shows a detail view of the first end 14 of barrel 12.

The barrel pin 122 secures the first end 14 of the barrel 12 to thehandle 62.

The locating plate 110 is secured to the first end 14 of the barrel 12by the retaining pin 114. The retaining pin 114 may be a nut and bolt oran alternative type of fastener.

The retaining pin 114 passes through a hole in the first end 14 of thebarrel 12 and through a slot 128 in the transfer rod 44.

The slot 128 in the transfer rod 44 allows for the linear movement ofthe transfer rod 44.

The locating plate 110 is secured to the handle by two locating platescrews 112. The locating plate screws 112 pass through a slot in thelocating plate 110. The slot in the locating plate allows movement ofthe locating plate 110 relative to the handle 62 for calibrationpurposes. This calibration is described in more detail below.

An end cap 104 is located in the first end 46 of the transfer rod 44.The second end 92 of the second lever 88 presses against the end cap104.

A return spring 130 is located within the first end 46 of the transferrod 44 between the end cap 104 and the retaining pin 114.

Calibration

The closure of the surgical clips to the correct position is set by afirst end stop formed by the stop face 55 of the pusher 50 abutting thecrimping lever 20. The position of this first end stop is notadjustable, being governed by the dimensions of the pusher 50 and thecrimping lever 20.

The locating plate 110 provides a second end stop feature by limitingmovement of the trigger 28. The position of this second end stop must beadjusted to match the first end stop position, during the assembly ofthe applicator.

The second end stop feature provides the surgeon with clear, tactilefeedback that the trigger has been depressed sufficiently to fully closeand secure the surgical clip.

An additional benefit of the second end stop is that it limits the forcewhich the surgeon can apply via the trigger to the compound levermechanism, which might otherwise damage the handle or other parts of theapplicator.

The adjustment of the position of the second end stop is made by movingthe locating plate 110 within the handle 62 until the second end stopposition matches the first end stop position. The locating plate 110 isthen secured to the handle 62 with the locating plate screws 112.

Operation

The applicator 10 is intended to be used single-handedly. The trigger 28is intended to be operated by the first and second fingers with thehandle 62 accommodating the remaining fingers.

When the trigger 28 is depressed it slides into the handle 62. There isminimal clearance between the trigger 28 and the handle 62. When theapplicator is being used, the surgeon will be wearing surgical gloves.Any substantial gap between the trigger 28 and the handle 62 may resultin the surgical glove becoming trapped and torn, which could createhygiene problems.

Movement of the trigger 28 results in the actuating pegs 82 on thesecond end 76 of the first lever 72 being moved by the actuating slot 36in the trigger 28.

As the first lever 72 rotates around the first pivot pin 80, the firstend 90 of the second lever 88 slides along the length of the actuatingsurface 78 of the first lever 72, thereby rotating the second lever 88about the second pivot pin 96.

Rotational movement of the second lever 88 causes the second end 92 ofthe second lever 88 to press against the end cap 104 of the transfer rod44 causing linear movement of the transfer rod 44.

Linear movement of the transfer rod 44 and pusher 50 towards the secondend 16 of the barrel 12 causes the second end 54 of the pusher 50 topush against the crimping lever 20 causing rotational movement about thepivot point of the crimping lever 20. This movement of the crimpinglever 20 results in the second crimping surface 22 of the crimping lever20 closing onto the first crimping surface 18 at the second end 16 ofthe barrel 12 resulting in the surgical clip being urged from an openposition to a closed position.

When the second crimping surface 22 reaches a position relative to thefirst crimping surface 18 in which the surgical clip is closed to thecorrect position, a first end stop limits further movement of thecrimping level 20. The first end stop is formed by the stop face 55 ofthe pusher 50 abutting the crimping lever 20. The first end stop ensuresthat the surgical clip is precisely closed to the correct position andis not “over-closed”.

Additional pressure applied to the trigger after the first end stop hasbeen actuated results in a second end stop coming into operation. Thesecond end stop is formed by the trigger directly contacting thelocating plate, thus further limiting the stroke of the mechanism.

When the trigger 28 is released, the return spring 130 urges thetransfer rod 44 and pusher 50 away from the second end 16 of the barrel12. Linear movement of the transfer rod 44 and pusher 50 away from thesecond end 16 of the barrel 12 causes the slot 53 at the second end 54of the pusher 50 to pull against the opening peg 24 of the crimpinglever 20 causing rotational movement about the pivot point of thecrimping lever 20. This movement of the crimping lever 20 results in thesecond crimping surface 22 of the crimping lever 20 opening away fromthe first crimping surface 18 at the second end 16 of the barrel 12.

What is claimed is:
 1. A hand-operable surgical clip applicator, theapplicator comprising: a barrel having a first end and a second end, thesecond end formed as a first crimping surface and being able toaccommodate a surgical clip; a crimping lever, the crimping leverpivotally connected to the barrel, the crimping lever having a secondcrimping surface and an opening peg, the second crimping surface beingin opposition to the first crimping surface, the first crimping surfaceand the second crimping surfaces being biased away from one another; anda pushrod, slidably located within the barrel, which may abut, and inuse does abut, the crimping lever and constrains the opening peg;wherein movement of the pushrod towards the second end of the barrelcauses the pushrod to push the crimping lever, further causing thesecond crimping surface to close onto the first crimping surface,thereby in use urging a surgical clip from an open position towards aclosed position.
 2. An applicator as claimed in claim 1 in whichmovement of the pushrod away from the second end of the barrel causesthe pushrod to pull the opening peg, further causing the second crimpingsurface to open away from the first crimping surface.
 3. An applicatoras claimed in claim 1 in which the pushrod includes a hollow portion,with a return spring being accommodated within the hollow portion.
 4. Anapplicator as claimed in claim 1 in which the barrel is formed from asingle piece of material.
 5. A hand-operable surgical clip applicator,the applicator comprising: a barrel, the barrel having a first end and asecond end, the second end formed to accommodate a surgical clip; acrimping lever; a trigger; and a handle; wherein the handle includes; afirst lever having a first end and a second end, the first end of thefirst lever being pivotally connected at the handle, the second end ofthe first lever being slidably connected to the trigger; and a secondlever having a first end, a second end and a centre region, the centreregion of the second lever being pivotally connected to the handle, thefirst end of the second lever being configured to slide along the lengthof the first lever, the second end of the second lever being adapted tooperate the crimping lever; the first lever and the second lever beingconfigured to provide a mechanical advantage between the trigger and thecrimping lever, movement of the trigger in use causing movement of thecrimping lever, resulting in a surgical clip being urged from an openposition to a closed position.
 6. An applicator as claimed in claim 5 inwhich the barrel includes a slot at its first end, the slotaccommodating the second end of the second lever.
 7. An applicator asclaimed in claim 5 in which the first end of the pushrod includes an endcap, the second end of the second lever pressing against the end cap. 8.An applicator as claimed in claim 1 or claim 5, the pushrod furthercomprises a transfer rod and a pusher, the pusher having a stop face,the transfer rod and pusher being slidably located within the barrel,the transfer rod and pusher being releasably connected together by abayonet joint, and the pusher abutting the crimping lever andconstraining the opening peg of the crimping lever.
 9. An applicator asclaimed in claim 8, the pusher being formed with sliding surfaces ateach of the first and second ends, the sliding surfaces configured toslide within the internal surface of the barrel, the portion of thepusher between the first and second ends having a smaller diameter thaneach of the first and second ends.
 10. An applicator as claimed in claim5 in which the trigger includes a visual indicator in at least one sidethereof, the visual indicator providing means indicative of anintermediate trigger position.
 11. An applicator as claimed in claim 10in which the barrel is located in the handle by a barrel pin, the barrelpin being secured to the handle.
 12. An applicator as claimed in claim5, in which the handle includes a locating plate, the locating platebeing secured to the barrel by a retaining pin, the locating plate beingfurther secured to the handle by a locating plate fastener.
 13. Anapplicator as claimed in claim 12 in which the pushrod includes a slot,the slot accommodating the retaining pin.
 14. An applicator as claimedin claim 8 in which the stroke of the pushrod is limited by the stopface of the pusher abutting the crimping lever.
 15. A hand-operablesurgical clip applicator, the applicator comprising: a barrel, thebarrel having a first end and a second end, the second end formed toaccommodate a surgical clip; a crimping lever; and a trigger, thetrigger co-located with the barrel, the trigger being adapted to operatethe crimping lever, causing the surgical clip to be forced from an openposition to a closed position; wherein the trigger is formed with apressing surface disposed on each of two opposing sides of the barrel.16. An applicator as claimed in any one of the preceding claims, inwhich at least one of the trigger, handle, first lever, second lever orlocating plate is formed from a material which becomes molten when theapplicator is exposed to the operating environment within a medicalautoclave.
 17. An applicator substantially as described with referenceto the accompanying drawings.